Hair today, gone tomorrow...

GAIL Porter turned more than a few heads in LA when she arrived to promote her latest TV series minus her long blonde hair. Instead, the Scots-born presenter sported a shaven head with a sassy red Mohican.

It's believed Porter suffered a bout of alopecia (hair loss) and, rather than disguising the problem with a new hairstyle or with a wig, chose to step out in style, declaring that bald is beautiful.

At Cannes in May, Natalie Portman also wowed fans on the red carpet with a shaven head, following her role as a freedom fighter in her next movie V for Vendetta.

But not everyone has the luxury of losing their hair for a multi-million-dollar movie. Many women will experience hair loss at some point (50 per cent by the age of 50, according to estimates), whether for genetic reasons, or as a result of stress, hormonal changes, illness or cancer treatments such a chemotherapy.

But the good news is that many types of hair loss are temporary, including the particularly devastating condition telogen effluvium, a dramatic shedding of the hair caused by stress or trauma, typically taking place three months after a traumatic event.

With hair loss such a common issue for women, it's worth everyone acquainting themselves with the facts about a lady's crowning glory:

1 Eat well. Nutritional deficiency is one of the commonest causes of hair loss, and extreme diets can cause hair to fall out. Marilyn Sherlock, chairman of the Institute of Trichologists, whose practitioners specialise in the care of the human scalp and hair, says: "If this is the cause, a well balanced diet will usually resolve it. Make sure you eat plenty of iron." Hair is made up of protein, so eat plenty of fish, meat, eggs, dairy products and pulses.

2 Hair loss can be a symptom of another medical problem, such as hormone imbalance or an under-active thyroid gland. If concerned, consult your GP.

3 Statistics suggest that between 20 and 40 per cent of mothers lose some hair in the months after childbirth due to sudden changes in the level of oestrogen in the body around this time. However, in most cases the hair will return to normal within nine to 12 months.

4 Another common cause of hair loss is alopecia areata, which causes small, round, bald patches and affects about one person in 100. It is thought to be an auto-immune disease, the result of which is that white blood cells attack the hair follicles. For more information on this condition, see www.patient.co.uk

5 Beware of miracle cures. "If you see products which claim to cure hair loss across the board, the chances of it doing anything whatsoever are nil," says Marilyn Sherlock. "On the other hand, treating specific hair loss with a specific treatment can be quite successful."

6 If you are worried, consult a trichologist - but make sure he or she is fully qualified. There are few legal controls on the profession, so find one via a professional body such as the Institute of Trichologists (www.trichologists.org.uk) or The Trichological Society (www.hairscientists.org).

7 Cover up in style. Kylie Minogue, currently being treated for breast cancer in Paris, was spotted recently wearing a jaunty polka-dot headscarf. A wide range of wig options is now available. Cancer support organisations offer useful databases. See, for example, www.cancerhelp.org.uk